Optimized Synthesis and Simple Purification of 2,5‐Diamino‐thiophene‐3,4‐dicarboxylic Acid Diethyl Ester

Abstract

A stable diamino thiophene was synthesized in high purity with a three‐fold increase in yield over previous reports via simple crystallization using inexpensive reagents.

Keywords:

• diamino thiophene
• Gewald reaction
• one‐pot reaction

Acknowledgments

The authors acknowledge financial support in part from the Natural Sciences and Engineering Research Council Canada, Canada Foundation for Innovation, Fonds de Recherche sur la Nature et les Technologies, and the Centre for Self‐Assembled Chemical Structures. M. B. thanks the Université de Montréal for a graduate scholarship, and S. V. thanks Le Ministère des Affaires Étrangères for a travel grant.